Island



(No Model.)

G. W. MATHEWSON.

POWER JACK.

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Patented Oct. 8, 1889.

INVINTH.

WHA/55555 e UNITED STATES PATENT FFICE.

GEORGE W. MATHEVVSON, OF OOVENTRY, RHODE ISLAND.

POWER-JACK.

SPECIFICATION forming part of Letters PatentNo. 412,518, dated October8, 1889. Application led December 26, 1888. Serial No. 294,616. (Nomodel.)

To all Whom 'it may concern:

Be it known that I, GEORGE 'W. MATHEw- SON, of Coventry, in the countyof Kent and State of Rhode Island,have invented certain new and usefulImprovements in Power-Jacks, of which the following is a full, clear,and eX- act description, reference being had to the accompanyingdrawings,.forming part of this specification.

This invention has reference to an improvement in power-jacks, by whichthe same are especially adapted for use in drawing or pulling out thespokes from the hubs of Wheels without injuring the hubs, and is alsoreadily adapted for pressing toget-her the boards' for floors beforenailing.

For these purposes the invention consists in the peculiar and novelconstruction of the frame in which the rack slides by providing; the endwith a concaved bearing to it the hub and with a hole through which apin is driven when the device is used for a Hoor-jack.

The invention further consists in providing the head of the rack-slidewith an adjustable clamping device, by means of which the v Vspoke canbe firmly held and drawn from the mortise of the hub, as will be moreful-ly set forth hereinafter.

' In the drawings similar numbers of reference indicate correspondingparts throughout.

Referring to the drawings, Figure 1 is a side view of the improvedpower-jack, showing the same supported on the hub and secured to a spoketo be drawn from the mortise of .the hub. Fig. 2 is a sectional view ofmy improved power-jack, and Fig. 3 is a top view of the same.

In the drawings, 4 designates the hub of a wheel; 5, the mortise orsocket in which the tenon of the spoke (5 is secured. The spokes ofwheels are firmly secured in the hub, and when on account of injury tothe spokes, or any one of them, a spoke has to be removed (which is amatter of very frequent occurrence in any blacksmith or wagon-makersshop) it is important that the spoke should be drawn out withoutinjuring the mortise, into which the new spoke must fit-accurately. Forthis purpose the spoke must be drawn out straight on the line of itsaxis'. In large wheels this is a slow and laborious process.

I have especially designed my improved 'sition by the stoppawl 25.

power-jack for the purpose of performing the extraction of spokes fromhubs, causing great saving in time -and preserving the mortise in thehub, while the improved power-jack is also useful for many otherpurposes for which power-jacks are used.

My improved power-jack consists of the metal standard 7, in which therack-bar 8 slides. The lower end of the standard 7 is provided with. aconcaved bearing 9, fitting the surface of the hub of a wheel, so as toform a iirm support for the power-jack when used for drawing spokes froma hub. It is also provided with the hole 10, through which the pin 11 isinserted when the power-jack is used for a floor-jack to secure thestandard to the floor-josts. The rack-bar is provided with the head 12,one side of which head has the serrated face I3. The links' I4 I4; areconnected at one endlby a har which carries the mclamp 15, the face ofwhich is serrated like the face 13, so as to secure a firm hold on thespoke, as is shown in Fig. 1.

To iirmly hold the links 14 to the head, I secure the bolt 16 in thehead 12 and provide both ends with ascrew-thread andwith clamping-nuts17. Into the sides of the head 12 and surrounding the bolt 1G, I insertthe circular disks 18 18, as shown in broken lines in Fig. 3. The outerfaces of these disks 1S are provided with projecting ribs which enterthe grooves 19 on the inner surface of the links 14. NVhen now the links14 are secured by the clamp-nuts 17, the ribs of the disks 18 enter thegrooves of the links and thus hold them firmly against strain on thelinks and still allow the links, and with the same the clamp 15, to turnon the bolt to adjust the clamp to the spoke.

The rack-bar is shown as provided with ratchet or saw teeth, as is alsothe pinion 20; but both may be provided with the usual gear-teeth. Thelever 2]. is hinged on the shaft 22, and on the shaft 22 theratchetwheel 23 (a part of which extends into a groove formed in theratchet-bar) is secured, having on each of its sides the pinions20,0peratin g the rack-bar 8. The pawl 24 connects the lever 21 with theratchet-wheel 23 and 0perates the pinions 20 in one direction to raisethe rack-bar 8, which is held in the raised po- The lever can ICO thenbe moved in the opposite. direction, the pawl 24C sliding over theratclietteeth of the Wheel 23.

Having thus described my invention, I claim as new and desire to secureby Letters Patent- 1. The combination, in a power-jack, of a headprovided with the bolt 1t, clamp-nuts 17, the disk 18, links 14, andclamp 15, constructed to operate as and for the purpose described.

2. The combination, with the head of t power-jack provided with the bolt16 and clamp-nuts 17, of the ribbed disk 18, the grooved links 14, andthe clamp 15, as described.

3. A power-jack consisting of the standard 7, the rack-ber 8, providedwi th saW-tootli-sectioned teeth and with the head 12, the pinion 20,the ratchet-Wheel 23, the lever 21, the pawl 24, connected With thelever 21, and the spring-pressed stop-pawl 25, pivoted in the standard7, constructed to engage with the saW-tooth-sectioned rack of therack-bar, as

GEORGE 1V. MATH EWSON Witnesses:

JOSEPH A. MILLER, JOSEPH A. MILLER, Jr.

